There has been a tendency that year by year exhaust gas regulations on vehicles are being tightened up, and it is expected that stricter exhaust gas regulations will be applied in the future. Thus, the electrification of an engine and its peripheral equipment is advanced as a measure against exhaust gas regulations, and an electric actuator is used in a control driving unit in many cases (for example, refer to Patent Literatures 1 and 2).
Driving methods for actuators are classified into ones of rotating type and ones of direct acting type. In an actuator of rotating type, a shaft rotates in a direction of rotation of a rotor. In an actuator of direct acting type, a shaft reciprocates in directions perpendicular to a direction of rotation of a rotor.